Sex when trying to get pregnant

Lots of factors can influence how likely it is for you or your partner to become pregnant. In the majority of cases, having sex is a great place to start your journey to conceiving a baby.

For a woman to become pregnant, a man's sperm need to be placed into her vagina. This usually happens when a man’s erect penis is inserted into a woman’s vagina during sex and a fluid called semen is ejaculated from the man’s penis into her vagina.

Sperm usually passes through the womb to reach the fallopian tube. In the fallopian tube at least one sperm must meet the ovum (egg) for fertilisation to happen.

Frequent sex is the best way to conceive

Have sex every 2 to 3 days to increase your chances of getting pregnant. This may not always be practical. For example, you or your partner may need to travel for work. In such situations, you may decide to schedule when to have sex together.

Ovulation and the best time to have sex

A woman is more likely to get pregnant if she has sex around the time of ovulation. Ovulation is when the ovary releases an egg which can be fertilised. This usually occurs 12 to 16 days before a woman's next period.

It can be difficult to know exactly when a woman is ovulating. Sperm can live for up to 7 days in a woman’s body. Even if you have sex days before ovulation you could still become pregnant.

How to predict ovulation

Cycle length

Ovulation usually occurs 12 to 16 days before your next period. If you have regular periods, you may be able to predict when this is. There are a variety of smartphone apps available that could help with this.

Body temperature

Your body temperature usually rises when you ovulate and remains high until your next period. Take your temperature every morning before getting out of bed. You may notice a pattern. A basal body thermometer may be more accurate.

Cervical mucus

The fluid from your cervix changes at different times in your cycle. Four days before ovulation, your fluid becomes wet, slippery and stretchy like egg whites. Once you notice this, you know you are in your fertile period.

Ovulation prediction kits

You can buy ovulation prediction kits from the pharmacy, but they can be expensive. They test your urine to detect changes in hormone levels that show when you are ovulating.

When to talk to your GP

Under 35

If you are healthy and have not become pregnant after 12 months of trying.

Over 35

You should talk to your GP after 6 months of trying.

Health conditions

If you or your partner have any health condition, talk to your GP after 6 months of trying. Especially if your health condition requires monitoring or drug treatment.


It is a good idea to visit your GP for a check-up before trying to conceive. Women should make sure their smear tests are up to date - find out more about cervical smear tests.

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This project has received funding from the Government of Ireland’s Sláintecare Integration Fund 2019 under Grant Agreement Number 8.

Page last reviewed: 18 September 2018
Next review due: 18 September 2021